net/smtp でメールを送るサンプル

bulkmail.rb

#!/usr/bin/ruby
# -*- coding: utf-8 -*-

require 'net/smtp'
require 'nkf'
require 'time'

input_password = proc do
  STDERR.print "type password: "
  begin
    system("stty -echo")
    pass = gets.chomp
  ensure
    system("stty echo")
  end
  STDERR.puts
  pass
end

smtp_host = 'mx.example.jp'
smtp_port = 587
helo_name = 'hello.example.jp'
smtp_auth_user = 'john'
from = "test\@example.jp"
bcc = from
subject = NKF.nkf('-WMm0j', "テストメール")
body = NKF.nkf('-Wm0j', <<BODY)
テストメールです。
BODY
rfc822_date = Time.now.rfc822

context = OpenSSL::SSL::SSLContext.new
ssl_params = {}
ssl_params[:verify_mode] = OpenSSL::SSL::VERIFY_PEER
store = OpenSSL::X509::Store.new
store.set_default_paths
ssl_params[:cert_store] = store
context.set_params(ssl_params)

smtp = Net::SMTP.new(smtp_host, smtp_port)
smtp.set_debug_output $stderr
smtp.enable_starttls(context)
smtp.start(helo_name, smtp_auth_user, input_password.call, :login) do |conn|
  [
    "example\@example.jp",
    "sample\@example.jp",
    "test\@example.jp",
  ].each do |to|
    message = <<-DATA
From: #{from}
To: #{to}
Subject: #{subject}
Date: #{rfc822_date}
Mime-Version: 1.0
Content-Type: text/plain; charset=ISO-2022-JP
Content-Transfer-Encoding: 7bit

#{body}
    DATA
    conn.send_message message, from, to, bcc
  end
end